A stationary ventilation known in the prior art is disclosed in the pamphlet of Korean registered patent assigned Serial No. 10-436840, and is illustrated in FIG. 1 enclosed herewith.
As shown in FIG. 1, a stationary ventilating device described in the pamphlet comprises a base 140, a plurality of first airflow-guiding plates 120 stacked-up and assembled on the base 140, a plurality of guiding members 130 each of which is interposed between the first airflow-guiding plate 120, a second airflow-guiding plate 100 installed in the uppermost story in the device and combined with the guiding member 130 on the uppermost first airflow-guiding plate 120, a fan for compulsory ventilation (not shown) which is installed inside the base 140, wherein each of the plurality of first airflow-guiding plates 120 and the second airflow-guiding plate 100 is provided with aperture 141 and 143 respectively for receiving a bolt 141 which is fixed by means of a nut 143, whereby the plurality of first airflow-guiding plates 120 and the second airflow-guiding plate 100 are stacked up and assembled together.
However, the stationary ventilating device in accordance with the above-mentioned prior-art has problems as follows.
The second airflow-guiding plate 100 and the plurality of first airflow-guiding plates 120 stacked up under the second airflow-guiding plate 100 have the same angle of lateral slope, and thereby an uppermost room is formed by the height of the slope. A portion of the airflow rises and converges into the uppermost room and as a result, a resisting force is generated due to the converged airflow. In other words, there is the problem that ventilating the rising airflow efficiently is impossible due to the resisting airflow generated in the uppermost room.